Lamontichthys maracaibero Taphorn & Lilyestrom, 1984

Fig. 12

Lamontichthys maracaibero Taphorn & Lilyestrom, 1984a: 94-95, 98, fig.1, table 1 [original description; type locality: “ Venezuela, Zulia, Distrito Miranda, río Motatán in el Puente Tres de Febrero”; paratypes from río Motatán and río Ariguisá]; Taphorn & Lilyestrom, 1984b: 17, 29 [key and common name; lago Maracaibo, Venezuela]; Galvis et al., 1997: 88 [description, habits, common names, illustrations, río Catatumbo system in Colombia and Venezuela]; Provenzano et al., 1998: 11-12, 21, 23 [type listed]; Eschmeyer, 1998: 1014 [listed]; Mojica, 1999: 562 [listed]; Isbrücker, 2001: 29 [listed]; Ferraris Jr., 2003: 336 [listed]; Ferraris Jr., 2007: 264 [listed].

Diagnosis. Lamontichthys maracaibero differs from all congeners in the presence of a single plate (vs. two plates) between the pelvic-fin base and the anterior margin of the anus (Figs. 1 and 5).

Specimens of L. maracaibero larger than 150 mm SL possess a deeper body at the predorsal region (14.0-15.1%, n = 6, vs. 11.5-13.5%, n = 26) relative to the other species of Lamontichthys (except for L. parakana for which specimens larger than 150 mm SL were not available for comparison), forming a hump between the head and the dorsal-fin origin. Lamontichthys maracaibero is further distinguished from L. filamentosus and L. llanero by the semi-oval shape of the lower lip (vs. semicircular) (Fig. 9); and from L. llanero by the reduced number of lateroventral thoracic plates in specimens smaller than 50 mm SL (5 to 6 plates, vs. 7 to 10), and from L. stibaros, L. avacanoeiro, and L. parakana by having the snout totally covered with plates at its anterior tip (vs. presence of an area lacking plates) and by the teeth with short cusps (vs. long) (Fig. 3). The specimens of Lamontichthys maracaibero larger than 100 mm SL also differs from L. stibaros, L. avacanoeiro, and L. parakana in the relatively shorter head (16.7-17.8%, vs. 19.8-23.0% SL) and shorter dentary (14.8-19.1%, vs. 18.4-23.4% HL). Morphometric and meristic data are presented in Table 2.

Geographic distribution. Lago Maracaibo basin (Fig. 2).

Material examined (9 specimens; 63.4-210.2 mm SL): Colombia: ICNMHN 2166, 5, 149.1-210.2, Catatumbo, Santander, río Catatumbo, córrego La Gabarra . Venezuela: Trujillo: lago Maracaibo drainage: MCNG 3592, 1, 154.9, holotype; MCNG 3593, 1 (of 4), 63.4, 1 cs *, 83.8, paratypes, Betijoque, río Motatãn, bridge “Tres de Febrero”. Zulia: INHS 35473, 1, 131.3, río Santa Rosa .